Cummins diesels recalled over poorly aging catalysts

"dieseldub" (dieseldub)
07/31/2018 at 18:29 • Filed to: None

In a report from !!!error: Indecipherable SUB-paragraph formatting!!! , they briefly explain that CARB has been working with Cummins on a solution to this problem. It’s not a defeat device, the vehicles were in fact perfectly clean when new, but the catalysts that reduce the emissions to legal levels were not aging well and eventually caused excess emissions of NOx (as always, the one big bugaboo for diesels—on everything else they’re quite clean while equipped with DPFs).

Satisfied that the longevity of updated components is sufficient, there is now a recall in place to remove the poorly aging catalysts and install longer lived units.

Some have commented that it seems next to impossible for diesels to meet emissions reliably and maybe the technology should be abandoned altogether. But to some of us with more experience in the field and with how manufacturers operate to obtain feedback from technicians and analyze failed parts, I would argue it’s more akin to the early smog days with gasoline engines before 3 way catalysts and electronic fuel injection with a feedback loop.

This is simply new technology that needs time to mature and get better in every regard and the only way to get there is continual, massive investment in R&D and time to allow technologies to mature and have better feedback on their effectiveness and longevity in real world conditions over the long term. At the end of the day, battery electrics will not be able to provide everyone on the scale we currently have using internal combustion. At least not for some time to come yet. More efficient internal combustion processes like diesel will be needed in the interim. And, as some CARB officials have pointed out, they in fact like diesels—when they meet their tough regulations. Aside from the NOx bugger, they’re cleaner than gas engines. Less soot, less carbon monoxide, less hydrocarbon emissions , less CO2 because of their increased efficiency (NOTE: CO2 is not a harmful gas, we in fact trade off for having more CO2 from tailpipes to improve air quality with most catalytic processes , it’s just that CO2 is a big reason why we have climate change).

Here’s to hoping manufacturers can make emissions equipment live up to the “million mile engine” reputation diesel engines tend to have.

DISCUSSION (4)

gogmorgo - rowing gears in a Grand Cherokee > dieseldub
07/31/2018 at 19:50

That’s definitely something that’s noticeable, the “unreliable” diesel emissions controls thing. There’s a learning curve for sure with the manufacturers, yeah, but there’s also one for the operators. I work in the shop for a fairly substantial fleet, and we have quite a few different crews running diesels of all sizes, from the baby Duramax C olorados right up to the big Cumminses in our a Western Star highway plows. There’s a couple different approaches to driving in our fleet. There’s type A, which is to bag the shit out of everything; and type B, which is the “mature” or “responsible” or “grandma” sort of driving. The diesels we have coming back for recurring issues are generally the ones run by the type B drivers. The type A drivers come back for other reasons, but for the most part they’re okay. The type B drivers who tow or haul heavy loads on a regular basis don’t really seem to have as many issues, either. The conclusion we’ve reached is that gentle driving under light loads isn’t good for emissions, whether it’s that they’re not getting hot or something else, no idea. But they also don’t seem to like extended idling, either.

With a bit of education on our operators parts, we see a lot fewer issues with the emissions equipment. And it basically comes down to throwing out the rule book on diesels your grandpa taught you.

dieseldub > gogmorgo - rowing gears in a Grand Cherokee
07/31/2018 at 20:03

You got that right. In the light duty diesel/passenger car world, when people ask me about advice on getting a more fuel efficient vehicle, I first ask them a question: what kind of driving do you do most?

Because if most of your driving is stuck in traffic or stop and go city driving, I will flat out tell them a diesel is not for them. Better off with a hybrid.

If you cover a lot of miles per year, many of which are higher and more constant load highway driving, a diesel is the best thing out there. They’re better to drive in those conditions, too.

Don’t want to know how many cracked DPFs among other stupid failures I saw with diesel passenger cars that were mostly city driven...

Meanwhile, a customer of mine who drives like a mad man all up and down the West Coast, his 2013 Passat nearing 250,000 miles already, and not a single issue with the emissions components until just recently when a code popped up for the adblue heater... Those have been failing frequently enough that automakers will eventually improve the situation there as well. We’re still mostly assessing how the first generation of these technologies hold up with time.

TheD0k_2many toys 2little time > dieseldub
08/01/2018 at 03:49

I mean how many trucks still have the emissions systems still on them?

Pretty much every diesel truck here in MI on CL that came with that stuff is advertised as deleted as in the EGR and DPF.

gogmorgo - rowing gears in a Grand Cherokee > dieseldub
08/01/2018 at 14:16

Yeah, we’ve had a couple DEF heater issues too. Supposedly the baby Duramax’s just gives up around -10°F and shuts off, which is no b ueno when it’s not unusual for temperatures to approach -40 here. Fortunately for us those ones were still under warranty, so a call to roadside assistance, leave keys on the visor, and the truck dissapears, then reappears a week later without problems. It'll be interesting though when the warranty runs out.